Electrical discharge relay



July 28, 1936. s. RUBEN I ELECTRICAL DISCHARGE RELAY Filed Sept. 5, 1952 LINVENTOR SAMUEL RUBEN ATTORN EY Patented July 28, 1936 UNETED STATE .1115

ATE CFH 2,049,139 7 ELECTRICAL DISCHARGE RELAY Samuel Ruben, New Rochelle, N. Y.

Application September 3, 1932,

2 Claims. (01. 25047.5)

This invention relates to an electrical discharge relay device, and more particularly it relates to a relay device employing in a closed envelope the conductivity of an ionized path of mercury vapor to conduct current between a thermionic cathode and its cooperating anode. An object of the invention is to provide an electrical relay that is controllable within definite voltage values and is capable of conducting a relaby w ch one of the triodes directly controls the operation of the other through the direct connection between the cathode electrode of the control triode with the control electrode of the output triode. By the terms of the present invention one triode operates by an electronic discharge while the other functions by an ionic discharge through a metal, preferably mercury vapor.

The input or control set of elements is operated at a potential below the ionization potential of the mercury or other metal vapor employed, and the output triode operates above the ionization potential of that vapor.

In devices of this general type in the prior art using a mercury vapor discharge, it is necessary to use in conjunction with it the equivalent of an electron discharge type of tube for the control of the vapor tube, because of operating difficulties based upon inherent factors in the performance of those tubes, such as grid currents and temperature eifects.

By the terms of this invention only one tube is required and that has a high amplification efficiency brought about by connecting the elements as described in my said Letters Patent bearing Re-Issue Number 18,367, and my copending applications bearing Serial Numbers 553,052 and 580,020, filed respectively July 25, 1931 and December 10, 1931, that is, by connection of the cathode electrode of the control triode with the control electrode of the output triode, the cathode electrodes being insulated from each other and the anode electrodes having difierent potentials.

Fundamentally, in this tube the control set of Serial No. 631,655

elements is operated at a potential below the ionization potential of the metal to be vaporized, so that there is only an electron control.

The output set of elements is directly controlled by the other set, which latter is operated at a potential above the ionization potential of mercury which permits large currents to be dis-' charged through the tube.

To prevent cross current discharge between the active elements of the two triodes, the cathode and grid of each triode are enclosed within an anode element having narrow gaps through which the conductive electrodes and their supports pass, the gap constituting a de-ionization space, by reason of the maintenance thereof of transverse electrical fields of a potential gradient higher than that between the active emission surface of the cathode electrode and its cooperating anode electrode as described in my co-pending application bearing Serial Number 582,714 filed December 23, 1931. The deionization of any ionized mercury or other metal vapor tending to spread beyond the active area about the cathode is accomplished by an electricalfield maintained transversely to any leakage discharge beyond that area, the potential therefor being that derived from the normal drop of potential within the tube.

Because of the close spacing between the uncoated part of the cathode extending through the gap portion of the anode wall, there is an electrical field of a potential gradient higher than that between the active emission cathode surface and the anode. The equivalent of such close spacing may be obtained by extending the normal walls of the anode to a suificient distance beyond the oathode emission surface.

I have found that such a field completely deionizes any ionized metal vapor tending to discharge in a path other than that across the immediate space between the emission coated use upon the anode ends of a ceramic disc, such as magnesium oxide, with openings therethrough for the supporting leads. And while mercury vapor is preferred for use in this device, an amalgam of mercury and such alkaline metals as caesium, ribidium and sodium may be employed.

To more completely describe this invention reference is made to the accompanying figures, in which Fig. 1 diagrammatically illustrates a tube constructed in accordance with the terms of my invention and Fig. 2 is illustrative of an electrical circuit in which the tube using a double set of elements, is connected, or, it may be considered that each triode is in a separate vessel, the elements being connected as herein set forth.

Referring more particularly to Fig. 1, l, 2, '3 and 5 represent respectively the cathode, grid, plate and heater elements of one triode, la, 29., 3a and 5a. representing corresponding elements in the other triode. The cathodes are supported by leads 1 and 1a, the grids by leads 8 and 8a, and plates by leads 9 and 9a as mounted by members l0 and His, respectively. To support the various elements glass bead 6 is used, and as a source of mercury vapor an amalgam of mercury-potassium is placed within thin walled vessel I I, which also contains a small quantity of getter material, such as magnesium.

Referring more particularly to Fig. 2, in which elements corresponding to those shown in Fig. 1, bear like numbers, in the auxiliary equipment the source of input potential is indicated at L, B being a source of potential for controlling the electron emission between cathodeelectrode l and anode electrode indicated at R1, which may be of the resistance or inductive type. In the output set of elements control electrode 23. is negatively biased by battery Brwith respect to cathode electrode a, so

that under normal conditions there is a negligible ionized mercury discharge between cathode electrode la. and anode electrode 39.. .pedance in series with the negative bias potential source to control electrode '29.. At R is a resistance potentiometer device for varying the potential to anode electrode across the anode electrode current supply shown here as generator G. 7

It is to be noted that the cathode electrode l of the control triode is connected to the control electrode 29, of the other triode, so that an impedance change between cathode elect-rode I and plate 3, causes a potential change on-control elec trode 2a. Thus, if the normal bias of grid 2,, is

3. Through transformer T the cathodes are heated by conduction and the load is At Z is an im--v 3; this is connected,

such as to prevent the ionic discharge between cathode electrode Ia and anode electrode 3a, by decreasing the impedance between cathode electrode I and anode electrode 2, as by reducing the negative bias in the control electrode 2, there is a resultant decrease of negative bias on control electrode 29., with an attendant large current flow which is characteristic of ionized mercury vapor discharges.

A desirable or essential method of operation which allows the direct control of this tube by such limited current supply sources as photoelectric cells, is to maintain the control anode electrode 2 potential below the ionization potential of mercury vapor as, for example, below ten volts. Thus, in the same device by the combina- "tion and connections shown there is a heavy curvrent ionic discharge for operating a mechanism, yet controlled by an electron a high degree of sensitivity,

discharge, allowing negligible current consumptionpand permitting the use of readily replaceable p With the elements of the separate triodes properly connected, each triode may be placed within a separatecontainer so that between theelementsof, the first triode there is an electron dischargeend between the elements of the other, an ionic. discharge; there being thus made provision for the prevention of leakage tween the triodes,

What I claim is:

l. A relay tube comprising a sealed envelope containing an ionizable medium comprising a mercury amalgam, an electron discharge assembly comprising a cathode, an anode and a control element, an ionic discharge assembly comprising discharge bea cathode, an anode and a control element, the

cathode of the electron discharge assembly being connected to the control electrode of the ionic discharge assembly,'blocking means at the terminals of the ionic discharge assembly for confining the discharge thereof to the space between cathode and anode.

2. A relay tube comprising a sealed envelope containing an'ionizable medium, an electron discharge assembly comprising a cathode, an anode the anda control element, an ionic discharge assembly comprising a cathode, an anode and a control element, the cathode of the electron discharge assembly being connected to the control elec-" trode of the ionic discharge assembly, blocking means at the terminals of the ionic discharge assembly for confining the discharge thereof to the space between the cathode and anode.

SAMUEL RUBEN. 

